This invention relates to an image forming apparatus such as a printer, a copier or the like that uses electrophotographic technology.
Conventionally, there is proposed an image forming apparatus that forms a latent image by irradiating a surface layer of a photosensitive body whose thickness is less than or equals to 15 μm with the light beam whose diameter is less than or equals to 50 μm. The amount of the toner that forms a dot image is 1.2 times the amount of the toner that forms an area image, so as to enhance the image quality. Such a technology is disclosed in, for example, Japanese Laid-open Patent Publication No. 2000-108409 (particularly, in Page 3 and FIG. 1).
Recently, the image forming apparatus generally has the resolution of 600 DPI, and the development work to further enhance the resolution of the image forming apparatus has already started. Although an exposure (i.e., scanning) of high resolution image data has been accomplished, it is difficult to reproduce a single dot on a recording medium corresponding to such a resolution, and therefore it is difficult to obtain high quality print output corresponding to the high resolution image data. Particularly, the conventional image forming apparatus is not able to reproduce the minute dot whose diameter is approximately less than or equals to 25 μm, corresponding to the higher resolution of, for example, 1200 DPI and 2400 DPI.